More Evidence that City Living is the Greenest

Ever since David Owen's book Green Metropolis pushed forward the idea that cities are better for the planet, people have been debating if it's really so. New evidence says yes.

The study, from the journal Environment and Urbanization, says that the carbon emissions of cities vary widely.

Nonetheless:

"...some important trends emerge: low- and middle-income countries tend to have lower per capita emissions than high-income countries; dense cities tend to have relatively lower per capita emissions (particularly those with good transportation systems); cities tend to have higher emissions if in a cold climate zone. The most important observation is that there is no single factor that can explain variations in per capita emissions across cities; they are agglomerations of a variety of physical, economic and social factors specific to their unique urban life."

Jess Zimmerman at Grist sums it up:

"...while cities have the highest emissions per square mile, suburbs have far and away the highest emissions per person. Yeah, a single acre in New York is going to pollute more than an acre of strip mall in Scottsdale, but that's because everyone's stacked like Ikea cabinets. On a per-person basis, cities rule and strip malls drool."

Full Story: New evidence cities rule and suburbs drool

Comments

Comments

Emissions per capita not necessarily the right metric

I'm going out on a limb here, but the article mentions emissions per square mile more than once and does not really address the most important aspect of using a statistic with an area measurement in the denominator. The earth for most human perspectives has a fixed area which makes area-based statistics much more reliable. With a per-capita statistic, you always have to deal with the uncontrolled factor of global population increases. While emissions are tied to human activities and density is a driver of efficiency (aka reductions) in emissions, there needs to be recognition that the carrying capacity of the planet is fixed by area. Density is good - it forces the systems acting upon the earth to become more efficient. But comparing emissions/capita and emissions/sq.mi. is not a sounds statistical comparison: they have different units. All that the two number really prove is that there is some proportionate increase in emissions per unit area and some proportionate decrease in emissions per capita - not whether one is better than the other.

It would be great for Jess Zimmerman to take a look into the concept of carrying capacity: how much food, water, energy, and population can one square mile support? While I don't have the specific numbers to present here either, it stands to reason that since resources are fixed and area is fixed then a given square mile can only support a certain population within the current means of technology. Since technology is always approaching the limit of conservation of mass/energy then population capacity is at some point fixed. New York is a classic case as one of the first modern cities and probably represents to a certain extent the idea of carrying capacity; however, I would argue that Paris might be a more logical case study due to the relatively strict development density standards maintained there over decades.

Interesting piece - just looking for more research than opinion.

City Living is Greenest

While I do agree that the suburbs of the last 50 years have their issues; I, along with millions of Americans, have no desire to dwell in a highly concentrated urban environment with its issues of crime, urban decay, troubled public schools, a bankrupt government, and pollution. And most concerning to me are the issues of public safety in this time of political and religous unrest. Where do you think the suicide bombers, car bombs, dirty bombs, and germ warfare releases are going to occur? And before you say it, no I'm not a supporter of any political party and I admit that big cities are exciting places to visit and yes the suburbs have many of the same problems as the big cities, I just don't want to live in a big city and I really get tired of reading all the articles by class room planners preaching that we must all move to big cities to save the earth. I say to those so called planners, move to India or China and live among people on top of people and you should be happy there. I would have to vote for small towns, small electric cars, small homes, reducing big truck hauling and getting back to rail for shipping, new urbanism, bikes, and local food production, and we should all vote against the movement for a global economy, its going to bring about the end of the U.S.A.

If you had to pay the full

If you had to pay the full cost of living in the suburbs, perhaps you might decide it's a better deal to live in the city. Till then, you are basically being paid to prefer the suburban life.

Note I said nothing about

Note I said nothing about cost because cost is irrelevant in the discussion. The question is whether it is mathematically valid to compare emissions/sq.mi. to emissions/capita and valid science says no. My comment asked for a discussion on the actual facts behind the opinion column, not a judgement on what lifestyle I "must be living" based on the comment I made. I do live in a city, not as dense as New York or Chicago, though. I car-share when I must, use the bus other times when weather doesn't allow bicycling, and bike to work weather permitting. Reserve the rhetoric, please.

Streetcar Suburbs

Unfortunately, the debate is so polarized that many people think the only choices are dense cities or sprawl suburbs.

There is a practical alternative: walkable suburbs, like the streetcar suburbs that were common in America 100 years ago. The New Urbanists have built new suburbs that are like these old streetcar suburbs.

Market reserach by the CNU has found that the majority of Americans prefer these walkable suburbs to auto-dependent sprawl suburbs. And they are just thinking of which place they would prefer to live in - not of the other costs of sprawl suburbs (such as oil shortages and global warming).

Small towns are not really a practical alternative, because most of the jobs are in the metropolitan areas. But streetcar suburbs can provide many of the benefits of small-town life.

I can't resist adding a link to my favorite picture of a streetcar suburb: http://preservenet.blogspot.com/2005/07/streetcar-suburbs.html As you can see, there are no cars or other vehicles in the picture: this was a place where people walked or used transit for all their trips.

Charles Siegel

Post Carbon America.

I, along with millions of Americans, have no desire to dwell in a highly concentrated urban environment with its issues of crime, urban decay, troubled public schools, a bankrupt government, and pollution.

...I would have to vote for small towns, small electric cars, small homes, reducing big truck hauling and getting back to rail for shipping, new urbanism, bikes, and local food production, and we should all vote against the movement for a global economy, its going to bring about the end of the U.S.A.

This is a decent articulation of the issue. Surely America will densify as gasoline prices go up to their true cost and carbon is taxed. Whether this and globalization's slowdown will ruin the U.S. of A. is a matter of perspective, of course.

Best,

D

It's not Cities vs. Suburbs

I am reposting a comment I made awhile ago for a different Planteizen article (http://www.planetizen.com/node/39422) that I think is relevant here:

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I think you really need to look deeper at the type of urban development and urbanization that is being proposed. Sure, there is lots of hoopla surrounding downtown revitalization projects that involve plenty of apartment towers, restaurants, bars and active urban living. But a lot of what is being proposed it ideally suited to families. Denser nodes around rapid transit stops that include a mix of uses (including places for families to shop), as well as a mix of housing types (including row houses with backyards and narrow-lot single-family homes with backyards) and plenty of public green space are all ideally suited to families with children.

The problem is that developers and NIMBY types often hijack the debate and frame it as "apartment towers vs. single family homes", and accuse people of wanting to turn their neighbourhoods into another downtown . It is precisely NOT that type of A vs. B thinking! It is about having a mix of land uses, activities and housing types in each neighbourhood so that not all young singles feel the need to live downtown and not all families need the need to live way out in the distant suburbs.

Nearly all denser mixed-use development proposals and projects I've seen have plenty of excellent choices for families. No one I've talked to has ever proposed only downtown-style living. Those in the "academic and intellectual world" have not only taken on the task, they've proposed excellent solutions. You just need to look at what's really on the table.
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No one is trying to say that everyone needs to live in a New York or Chicago-style big city. The point is the suburban developments can be done differently and made much more efficient while still maintaining everything people like about the suburbs.

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